Method of treatment for mental disorders

ABSTRACT

The invention relates to a medicament or a method for treating mental disorders, in detail, ADHD comprising lurasidone, or a combination of lurasidone and a D 4  receptor agonist.

TECHNICAL FIELD

The invention relates to a method for treating mental disorders, in moredetail, a novel method for treating ADHD.

BACKGROUND ART

Lurasidone [chemical name:(3aR,4S,7R,7aS)-2-{(1R,2R)-2-[4-(1,2-benzisothiazol-3-yl)piperazin-1-yl-methyl]cyclohexylmethyl}hexahydro-4,7-methano-2H-isoindole-1,3-dione]of the following formula is a compound having a pharmacological activityas an antipsychotic agent, which is characteristic of a high affinityfor dopamine D₂, serotonin 5-HT_(1A), 5-HT_(2A)5HT₇, and noradrenalineα_(2C) receptors, and characteristic of minimal to no affinity forhistamine H₁ and muscarinic M₁ receptors. Lurasidone possessesantipsychotic effects, antidepressant- or anxiolytic-like effects, andpharmacological profiles with potentially-reduced liability forextrapyramidal and CNS depressant side effects, which is expected to beused for the treatment of schizophrenia and bipolar disorder (PatentReference 1, Non-patent Reference 1).

Dopamine D₄ receptors are one of subtypes of dopamine receptors, whichare known as a target in the treatment of schizophrenia or Parkinson'sdisease.

Attention deficit/hyperactivity disorder (ADHD) is one of developmentaldisorders, which is characterized by inattention, hyperactivity, andimpulsiveness. The symptom includes difficulty in concentrating,overactivity, and inattention. Generally, the symptom is observed inchildren who are 7 year-old or younger. In addition, the symptomincludes inattention-predominant type which is not dominant inoveractivity. The incidence rate up to school-age is 1-6%, and the rateof boys is higher than that of girls. ADHD had been thought to be adisease in children and be naturally improved in adults because thecases of hyperactivity decrease with aging. But, currently it is thoughtthat adults can suffer from ADHD.

As a drug therapy for ADHD, central stimulants are used in order toraise patient's arousal level, and methylphenidate hydrochloride ismainly used in America and a sustained preparation of methylphenidatehas been approved in Japan as a medicament for treating ADHD inchildhood. In addition, atomoxetine hydrochloride which is anoradrenaline reuptake inhibitor is also acceptable in Japan, but theapplied patients thereof are limited to children. Thus, there is nomedicament therefor for adults in Japan. In America, methylphenidate isacceptable for adults, but, it is indicated that methylphenidate has thesame side-effect as psychostimulants such as amphetamine,methamphetamine, and cocaine.

Risperidone, which is one of serotonin/dopamine antagonists (SDAs), hasbeen reported in connection with ADHD (Non-patent Reference 2). However,there has not been any study about the improvement of attention functionin ADHD using risperidone.

On the other hand, there is a report about the relationship betweendopamine D₄ agonist and ADHD (Non-patent References 3 and 4).

PRIOR ART Patent Reference

[Patent Reference 1] JP 5(1993)-17440 A (U.S. Pat. No. 5,532,372 A)

Non-patent Reference

[Non-patent Reference 1] Exp Opin Invest Drugs 18(11): 1715-1726 (2009)

[Non-patent Reference 2] Neuropsychiatric Disease and Treatment 2008:4(1) 203-207.

[Non-patent Reference 3] Behav Pharmacol. 2008 Dec; 19(8): 765-76.

[Non-patent Reference 4] Neuropharmacology. 2003 Mar; 44(4): 473-81.

DISCLOSURE OF INVENTION Problem to Be Solved by the Invention

The purpose of the present invention is to provide a novel medicamentfor treating ADHD and a novel method therefor. In particular, thepurpose is to provide a medicament and a method useful for treatingattention function/impulsiveness in ADHD.

Means to Solve the Problem

The present inventors have extensively studied to reach the above objectand then has found that lurasidone or a pharmaceutically acceptable acidaddition salt thereof of the present invention, as well as a combinationof lurasidone or a pharmaceutically acceptable acid addition saltthereof and a D₄ receptor agonist of the present invention exhibit thedesired therapeutic effect increasing attention function and suppressingimpulsiveness caused by ADHD in primates model of ADHD. Based upon thenew findings, the present invention has been completed.

One embodiment of the present invention is directed to a method fortreating ADHD which comprises administering a therapeutically effectiveamount of lurasidone or a pharmaceutically acceptable acid addition saltthereof to a mammal in need thereof.

One embodiment of the present invention is directed to the above methodwherein treating ADHD is improving attention function in ADHD, i.e. amethod for improving attention function in ADHD which comprisesadministering a therapeutically effective amount of lurasidone or apharmaceutically acceptable acid addition salt thereof to a mammal inneed thereof.

One embodiment of the present invention is directed to the above methodwhich further comprises administering an additional psychotropic drug asa combination drug. The additional psychotropic drug used as acombination drug is preferably a D₄ receptor agonist, and the embodimentthereof is a method for treating ADHD which comprises administering atherapeutically effective amount of lurasidone or a pharmaceuticallyacceptable acid addition salt thereof and a therapeutically effectiveamount of a D₄ receptor agonist to a mammal in need thereof; inparticular, the method for improving attention function in ADHD.

The D₄ receptor agonist used herein is preferably one or moremedicaments selected from the group consisting of PD-168077, ABT-724,ABT-670, F-15063, A-412997, FAUC-327, Ro-10-5824, CP-226269, PIP-3EA,FAUC-299, FAUC-316, FAUC-179, FAUC-356, FAUC-312, A-369508, andpharmaceutically acceptable salts thereof; more preferably one or moremedicaments selected from the group consisting of PD-168077, ABT-724,ABT-670, F-15063, A-412997, FAUC-327, Ro-10-5824, CP-226269, PIP-3EA,and pharmaceutically acceptable salts thereof; and even more preferablyone or more medicaments selected from the group consisting of PD-168077,ABT-724, ABT-670, F-15063, and pharmaceutically acceptable saltsthereof.

Additional embodiment of the present invention is directed to a methodfor improving attention function in schizophrenia and/or bipolardisorder which comprises administering a therapeutically effectiveamount of lurasidone or a pharmaceutically acceptable acid addition saltthereof and a therapeutically effective amount of a D₄ receptor agonistto a mammal in need thereof.

Additional embodiment of the present invention is directed to apharmaceutical product for treating ADHD which comprises lurasidone or apharmaceutically acceptable acid addition salt thereof. In addition, thepharmaceutical product wherein treating ADHD is improving attentionfunction in ADHD is also an embodiment of the present invention.

In addition, one embodiment of the invention is directed to apharmaceutical product for treating ADHD which comprises lurasidone or apharmaceutically acceptable acid addition salt thereof and a D₄ receptoragonist. In addition, the pharmaceutical product wherein treating ADHDis improving attention function in ADHD is also an embodiment of thepresent invention.

Additional embodiment of the present invention is directed to a kit fortreating ADHD which comprises lurasidone or a pharmaceuticallyacceptable acid addition salt thereof. In addition, the kit whereintreating ADHD is improving attention function in ADHD is also anembodiment of the present invention.

In addition, one embodiment of the invention is directed to a kit fortreating ADHD which comprises lurasidone or a pharmaceuticallyacceptable acid addition salt thereof and a D₄ receptor agonist. Inaddition, the kit wherein treating ADHD is improving attention functionin ADHD is also an embodiment of the present invention.

Additional embodiment of the present invention is directed to use oflurasidone or a pharmaceutically acceptable acid addition salt thereofin the manufacture of a pharmaceutical composition for treating ADHD. Inaddition, the use wherein treating ADHD is improving attention functionin ADHD is also an embodiment of the present invention.

In addition, one embodiment of the invention is directed to use oflurasidone or a pharmaceutically acceptable acid addition salt thereofand a D₄ receptor agonist in the manufacture of a pharmaceuticalcomposition for treating ADHD. In addition, the use wherein treatingADHD is improving attention function in ADHD is also an embodiment ofthe present invention.

Additional embodiment of the present invention is directed to apharmaceutical composition comprising lurasidone or a pharmaceuticallyacceptable acid addition salt thereof for use in the treatment of ADHD.In addition, the pharmaceutical composition wherein the treatment ofADHD is improvement of attention function in ADHD is also an embodimentof the present invention.

In addition, one embodiment of the invention is directed to apharmaceutical composition comprising lurasidone or a pharmaceuticallyacceptable acid addition salt thereof and a D₄ receptor agonist for usein the treatment of ADHD. In addition, the pharmaceutical compositionwherein the treatment of ADHD is improvement of attention function inADHD is also an embodiment of the present invention.

Additional embodiment of the present invention is directed to use oflurasidone or a pharmaceutically acceptable acid addition salt thereofin the manufacture of a pharmaceutical composition for treating ADHDwhich is administered in combination with a D₄ receptor agonist. Inaddition, the use wherein treating ADHD is improving attention functionin ADHD is also an embodiment of the present invention.

Additional embodiment of the present invention is directed to use of aD₄ receptor agonist for potentiating the efficacy of lurasidone or apharmaceutically acceptable acid addition salt thereof for treatingADHD. In addition, the use wherein treating ADHD is improving attentionfunction in ADHD is also an embodiment of the present invention.

Additional embodiment of the present invention is directed to use oflurasidone or a pharmaceutically acceptable acid addition salt thereoffor potentiating the efficacy of a D₄ receptor agonist for treatingADHD. In addition, the use wherein treating ADHD is improving attentionfunction in ADHD is also an embodiment of the present invention.

Additional embodiment of the present invention is directed to amedicament for treating ADHD which comprises lurasidone or apharmaceutically acceptable acid addition salt thereof. In addition, themedicament wherein treating ADHD is improving attention function in ADHDis also an embodiment of the present invention.

In addition, one embodiment of the invention is directed to a medicamentfor treating ADHD which comprises lurasidone or a pharmaceuticallyacceptable acid addition salt thereof and a D₄ receptor agonist. Inaddition, the medicament wherein treating ADHD is improving attentionfunction in ADHD is also an embodiment of the present invention.

In addition, one embodiment of the invention is directed to a medicamentfor treating ADHD which comprises lurasidone or a pharmaceuticallyacceptable acid addition salt thereof for the administration incombination with a

D4 receptor agonist. In addition, the medicament wherein treating ADHDis improving attention function in ADHD is also an embodiment of thepresent invention.

In addition, one embodiment of the invention is directed to a medicamentfor treating ADHD which comprises a D₄ receptor agonist for theadministration in combination with lurasidone or a pharmaceuticallyacceptable acid addition salt thereof. In addition, the medicamentwherein treating ADHD is improving attention function in ADHD is also anembodiment of the present invention.

The improvement of attention function in ADHD of the present inventionincludes improvement of attention deficit, hyperactivity disorder, etc.,in more detail, improvement of impairment in a continuous concentration,improvement of a diminished rapid-reaction, improvement of a reducedactivity, etc.

Preferably, the D₄ receptor agonist used herein includes, but is notlimited thereto, the compounds listed in the following table andpharmaceutically acceptable acid addition salts thereof. More preferableD₄ receptor agonist includes PD-168077, ABT-724, ABT-670, F-15063,A-412997, FAUC-327, Ro-10-5824, CP-226269, PIP-3EA, and pharmaceuticallyacceptable acid addition salts thereof, and even more preferably,PD-168077, ABT-724, ABT-670, F-15063, and pharmaceutically acceptableacid addition salts.

The D₄ receptor agonist of the present invention may be used in acombination of two or more D₄ receptor agonists.

TABLE 1 Drug Name [CAS Reg. No.] Compound Name (Structure) ReferencePD-168077 [190383-31-4]

WO 2002041894 ABT-724 [474417-17-9]

WO 2003/076431 WO 2002/088093 ABT-670

WO 2003/099266 F-15063 [680203-70-7] [680203-72-9 (fumarate)]

WO 2007/104872 WO 2004/035561 A-412997 [630116-49-3]

US 2003/229094 WO 2003/099266 FAUC-327

Bioorganic & Medicinal Chemistry Letters 12 (2002) 633-636 Ro-10-5824[189744-46-5]

WO 1997/013759 CP-226269

US 2006/172995 U.S. Pat. No. 7,235,661 PIP-3EA

J. Med. Chem. 2006, 49, 3938- 3947 FAUC-299 [313972-96-2]

J. Med. Chem. 2000, 43, 4563- 4569 FAUC-316 [313973-04-5]

J. Med. Chem. 2000, 43, 4563- 4569 FAUC-179

Bioorganic & Medicinal Chemistry Letters 11 (2001) 2533-2536 FAUC-356

Bioorganic & Medicinal ChemistryLetters 12 (2002) 1937- 1940 FAUC-312

Bioorganic & Medicinal Chemistry Letters 13 (2003) 851-854 A-369508

US 2003/229094 WO 2003/099266

Effect of the Invention

Lurasidone or a pharmaceutically acceptable acid addition salt thereofof the present invention is useful for treating ADHD, in particular, forimproving attention function in ADHD. In addition, the effect oflurasidone or a pharmaceutically acceptable acid addition salt thereofcan be enhanced by administering lurasidone or a pharmaceuticallyacceptable acid addition salt thereof in combination with a D₄ receptoragonist.

Further, the present invention can be also effective for improving abehavior disorder such as inhibition of aggression in ADHD; in moredetail, effective for aggression against self and/or others, hostility,hyperactivity, severe impulsiveness, etc.

In addition, the present invention can be also effective for improvingattention function in a patient suffering from schizophrenia and/orbipolar disorder.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 depicts a marmoset, acryl boxes with a piece of Baumkuchen, acage and the test pattern in EXAMPLE 1.

FIG. 2 shows the variation of the correct % between both results of theORD test wherein one was carried out before the oral administration ofhaloperidol and the other was carried out 2 hours after theadministration. The dot in the figure shows the variation of the correct% in each individual marmoset and the bar graph indicates the averagevalue in each treated group.

FIG. 3 shows the variation of the correct % between both results of theORD test wherein one was carried out before the oral administration ofclozapine and the other was carried out 2 hours after theadministration. The dot in the figure shows the variation of the correct% in each individual marmoset and the bar graph indicates the averagevalue in each treated group.

FIG. 4 shows the variation of the correct % between both results of theORD test wherein one was carried out before the oral administration ofrisperidone and the other was carried out 2 hours after theadministration. The dot in the figure shows the variation of the correct% in each individual marmoset and the bar graph indicates the averagevalue in each treated group.

FIG. 5 shows the variation of the correct % between both results of theORD test wherein one was carried out before the oral administration ofolanzapine and the other was carried out 2 hours after theadministration. The dot in the figure shows the variation of the correct% in each individual marmoset and the bar graph indicates the averagevalue in each treated group.

FIG. 6 shows the variation of the correct % between both results of theORD test wherein one was carried out before the oral administration oflurasidone hydrochloride and the other was carried out 2 hours after theadministration. The dot in the figure shows the variation of the correct% in each individual marmoset and the bar graph indicates the averagevalue in each treated group. Note that “Lurasidone (mg/kg, p.o.)” shownin FIG. 6-8 means the dose of lurasidone hydrocholide.

FIG. 7 shows the variation of the correct % in single administration ofL-745,870 or in the combined administration with lurasidonehydrochloride (10 mg/kg, p.o.). The dot in the figure shows thevariation of the correct % in each individual marmoset and the bar graphindicates the average value in each treated group.

FIG. 8 shows the variation of the correct % in single administration ofRo 10-5824 or in the combined administration with lurasidonehydrochloride (3 mg/kg, p.o.). The dot in the figure shows the variationof the correct % in each individual marmoset and the bar graph indicatesthe average value in each treated group.

BEST MODE FOR CARRYING OUT THE INVENTION

Lurasidone may be used in form of the free base, optionally in form ofits pharmaceutically acceptable acid addition salt and/or optionally inform of the hydrate and/or solvate thereof. Suitable acid addition saltsinclude, for example, those of the acids selected from succinic acid,hydrobromic acid, acetic acid, fumaric acid, maleic acid,methanesulphonic acid, lactic acid, phosphoric acid, hydrochloric acid,sulphuric acid, tartaric acid and citric acid. Mixtures of theabove-mentioned acid addition salts may also be used. Amongst theaforementioned acid addition salts, the hydrochloride and thehydrobromide, particularly the hydrochloride, are preferred.

The present invention includes prodrugs of lurasidone or apharmaceutically acceptable acid addition salt thereof and a D₄ receptoragonist. In general, such prodrugs are functional derivatives of thecompounds of this invention which are readily convertible in vivo intothe required compound.

The exemplified prodrugs of the invention, but are not limited to,include the following types:

Phosphate ester prodrug for hydroxyl or amine group of the parent drug.

Carbonate or carbamate prodrug for carboxyl, hydroxyl or amine group ofthe parent drug.

Amide prodrug for carboxylic acid or amine group of the parent drug.

Amino acid-attached prodrug for carboxylic acid or amine group of theparent drug.

Oxime prodrug for ketone, amidine or guanidine group of the parent drug.

The prodrugs of the invention can be prepared, for example, by meansdisclosed in Nature Reviews Drug Discovery 7; 255-270 (2008); or Journalof Medicinal Chemistry 2005, 48 (16), 5305-5320.

The term “therapeutically effective amount” shall mean the amount of adrug or pharmaceutical agent that will elicit the biological or medicalresponse of a tissue, system, animal or human that is being sought by aresearcher or clinician.

The terms “treating” and “treatment” used herein include any treatmentof the disease (e.g. improvement of the symptoms, relief of thesymptoms, arrest of the development of the symptoms, etc.) as well asany prevention of the disease (e.g. prevention of the onset and/orprogression of the disease).

As used herein, the term “pharmaceutical product” is intended toencompass a product comprising the specified ingredients in thespecified amounts, as well as any product which results, directly orindirectly, from combination of the specified ingredients in thespecified amounts.

The term “ADHD” used herein means attention deficit/hyperactivitydisorder, in more detail, one of developmental disorders, which ischaracterized by inattention, hyperactivity, and impulsiveness. Thesymptom includes difficulty in concentrating, overactivity, andinattention.

In addition, the improvement of ADHD includes inhibition of aggression,and the specific behavior disorder of aggression includes aggressionagainst self and/or others, hostility, hyperactivity, severeimpulsiveness, etc.

The improvement of impairment in a continuous concentration, theimprovement of a diminished rapid-reaction, and the improvement of areduced activity, which are examples of the improvement of attentionfunction in ADHD of the present invention, can be evaluated byvisual/perceptual seeking and/or systematic/continuous listening as amarker of the improvement.

In the combination of the present invention, lurasidone or apharmaceutically acceptable acid addition salt thereof and a D₄ receptoragonist may be administered separately or together in one pharmaceuticalcomposition. In addition, the administration of one element of thecombination of the present invention may be prior to, concurrent with,or subsequent to the administration of the other element of thecombination. These ingredients may be formulated into a single dosageform or two separate ones.

Lurasidone and a D₄ receptor agonist of the present invention can beeasily reacted with a pharmaceutically acceptable acid to form a saltthereof. The acid includes an inorganic acid such as hydrochloric acid,sulphuric acid, phosphoric acid, and hydrobromic acid; and an organicacid such as oxalic acid, maleic acid, fumaric acid, malic acid,tartaric acid, citric acid, and benzoic acid. A preferable salt oflurasidone includes the hydrochloride thereof.

The active ingredients of the present invention (lurasidone or apharmaceutically acceptable acid addition salt thereof, or thecombination of lurasidone or a pharmaceutically acceptable acid additionsalt thereof and a D₄ receptor agonist) may be administered by oral,parenteral (e.g., intramuscular, intraperitoneal, intravenous orsubcutaneous injection, or implant), buccal, nasal, vaginal, rectal,sublingual, or topical (e.g., ocular eyedrop) routes of administrationand may be formulated alone or together, in suitable dosage unitformulations containing conventional non-toxic pharmaceuticallyacceptable carriers, adjuvants and vehicles appropriate for each routeof administration.

Lurasidone and a pharmaceutically acceptable acid addition salt thereofof the present active compound can be orally administered in a neededamount suitable for the active ingredient, as a generally-used dosageform such as tablet, capsules, syrup, and suspension, or parenterallyadministered as an injection form such as solution, emulsion, suspensionand patch.

The above-mentioned drug form can be prepared by formulating the activecompound with conventional additives such as carrier, excipient, binder,and stabilizer. In the case of injections, for example, acceptablebuffer, solubilizer, isotonic agent and pH adjuster can be also used.

The dosage of the active ingredients of the present invention is notlimited, but it can vary depending upon dosage amount of each activeingredient, frequency of administration, administration form, conditionof a patient suffering from the disease. For example, lurasidone or apharmaceutically acceptable acid addition salt thereof of the presentinvention can be orally administered in a dosage of 1-200 mg, preferably20-160 mg, per day for an adult, and once to several times a day. The D₄receptor agonist can be orally administered in a dosage of 1-600 mg perday for an adult, and once to several times a day.

When these active ingredients are prepared in a single dosage form, theD₄ receptor agonist is generally contained in 0.1 to 10 parts,preferably 0.3 to 3 parts, by weight per one part by weight oflurasidone or a pharmaceutically acceptable acid addition salt thereof.And, the drug combination may include the sum of the ingredients in0.1-70% (w/w) in the preparation, but not limited thereto.

EXAMPLE

Hereinafter, the present invention is further illustrated by Examples,but should not be construed to be limited thereto.

Example 1 (Method)

ORD test (object retrieval with detour test) is already reported as amethod for evaluating executive function (attentionfunction/impulsiveness) in primates. The present inventors have foundthat the method is useful as a model experiment for evaluating ADHD,then carried out the following test according to the method.

Male and female common marmosets having body weights of 250-450 g wereused. Haloperidol, clozapine, olanzapine, risperidone, and lurasidonehydrochloride were separately suspended in 0.5% methylcellulose (MC),and then each suspension was orally administered in a dose of 5 mL/kg tothe marmosets. On the other hand, L-745,870 which is a D₄ antagonist,and Ro 10-5824 which is a D₄ agonist were separately dissolved insaline, and then each solution was intramuscularly administered to thefemoris area in a dose of 0.5 mL/kg.

According to the method described in the literature (Psychopharmacology(2008) 196: 643-648) which was partially modified, the ORD test wascarried out as follows (see FIG. 1).

(Training for ORD Test)

Clear acrylic cubic boxes (dimensions: 4 cm×4 cm×4 cm) with one openside are set as the thick frames shown in FIG. 1. In each of the boxes,0.3-0.5 g of Baumkuchen as a food reward is placed at the point of eachtriangle in FIG. 1. The marmoset can reach out from the cage (shown asdotted line region) to obtain the reward placed in the acrylic box. FIG.1 is a view from the directly above. Amongst the situations between eachdirection of the box and each position of the reward, 5 patterns (lineof sight, left outside, left inside, right outside, and right inside)are defined as “easy task”, and the other 2 patterns (left deep, andright deep) are defined as “difficult task”. It is recorded as “correct”when the test animal can obtain the reward in one trial, while it isrecorded as “incorrect” when the animal can obtain the reward in thesecond trial or later.

The ORD test is carried out in the order described in the followingtable without any interval between each trial, which is referred to as“one series”. The marmoset is made to be trained with the one seriesonce a day.

TABLE 2 Trial Position of number the reward Level 1 Line of sight Easy 2Line of sight Easy 3 Right outside Easy 4 Right deep Difficult 5 Rightoutside Easy 6 Right inside Easy 7 Right deep Difficult 8 Left outsideEasy 9 Left deep Difficult 10 Left outside Easy 11 Left inside Easy 12Left deep Difficult 13 Left deep Difficult 14 Right deep Difficult 15Left deep Difficult 16 Right deep Difficult 17 Line of sight Easy

The marmosets were trained with the ORD test at least 10 times, and thenthe trained marmosets were used in the following main test.

The main ORD test was carried out as follows.

(1) The ORD test is carried out before administering each test drug(former value). Hereinafter, the ORD test is done in one seriescontaining the 17 trials corresponding to the above-mentioned training.

(2) Two hours after administering each test drug, the same ORD test iscarried out again (latter value). In case of the combinedadministration, the first drug (lurasidone hydrochloride) isadministered; one hour later, the second drug (the D₄ antagonist or D₄agonist) is administered; and then the ORD test is done one hour afterthe second drug is administered.

(3) The variation of correct % in the Difficult task is calculatedaccording to the following formula in order to evaluate the effect ofeach drug. For example, in case that the “correct count” in thebefore-administration test (former value) is 3 and the “correct count”in the after-administration test (latter value) is 5, the “correct %” iscalculated to rise in 25% (=(5−3)/8×100%) based on the fact that thetrial count of the difficult task in each series is 8.

The variation of the correct % ={the difference between the both correctcounts in the difficult task (latter value−former value)}/8×100

(4) The amount of Baumkuchen is 0.5 g×17=8.5 g in one series. Themarmoset can be tested at most 2 sets per day, i.e. it has beenconfirmed that the marmoset can take at most 17 g of Baumkuchen per day,but, all the test marmosets cannot be satisfied with 17 g of Baumkuchen.

(5) In case that a marmoset treated with the drug is used again, themarmoset is given in 2 week-drug-holidays, and before the test it isconfirmed that the previous medication will not affect the test.

(6) 5 to 6 marmosets were used per one test group. When a marmoset(s)suffered from vomiting or cataleptic akinesia induced by the drug andthen the ORD test with the marmoset(s) could not be done, the data ofthe marmoset(s) were excluded. And, when the test for one drug is doneover 2 days, the solvent test (control group) is done in both the days.Thereby, in some cases, the control group can include the data using atmost 12 animals (6 animals×2 times).

(Result 1)

As shown in FIGS. 2 to 5, haloperidol, clozapine, risperidone andolanzapine in each single administration decreased the correct % of theORD test in a dose-dependent manner. On the other hand, lurasidonehydrochloride increased the correct % of the ORD test in adose-dependent manner as shown in FIG. 6. Namely, it was indicated thatlurasidone hydrochloride in single administration can improve attentionfunction in ADHD and suppress impulsiveness.

(Result 2)

Although the single intramuscular administration of L-745,870 which is aD₄ antagonist (10 mg/kg) had no effects on the ORD score as shown inFIG. 7, the combined administration of L-745,870 (3 mg/kg, i.m.) withlurasidone hydrochloride (10 mg/kg, p.o.) decreased the correct % whichwas increased by the administration of lurasidone hydrochloride. Itseems that lurasidone failed to decrease the ORD score because of itsweak D₄ antagonistic actions in contrast to the strong D₄/D₂ receptorantagonistic actions of SDAs (serotonin dopamine antagonists) other thanlurasidone.

(Result 3)

As shown in FIG. 8, the single administration of Ro 10-5824 which is aD₄ agonist increased the ORD score in a dose dependent manner. Also,when the administration of lurasidone hydrochloride (3 mg/kg, p.o.)which had no effects on the correct % was combined with theadministration of Ro 10-5824 (0.3 mg/kg, i.m.) which is also had noeffects on the correct %, the ORD score was significantly increased.These results suggest that the application of lurasidone as acombination drug with D₄ agonist could enhance the therapeutic effectsin ADHD therapy. Also, these results suggest a possibility that acompound having both SDA action and D₄ agonist action could be amedicament for treating ADHD. Among deficits in attention function whichare the symptoms of ADHD, in particular, such medication is expected toimprove continuous concentration, rapid-reaction and visual/perceptualseeking.

Example 2

According to the five-choice serial reaction time task test (5-CSRTtest) which is based on the procedure described in Neuropharmacology.2006 Aug; 51(2): 238-50. Epub 2006 May 6. or Brain Res Cogn Brain Res.2004 Apr; 19(2): 123-3, it is possible to evaluate the effect of thecompounds or the combination drugs of the present invention forimproving deficits in attention function which are the symptoms of ADHD,in particular, continuous concentration, rapid-reaction andvisual/perceptual seeking.

(Animals)

Common marmosets (male/female, 250-450 g weight) are used.

(Induction of Cognitive Impairment)

Transient cognitive impairment is induced in the marmosets by theintramuscular administration of ketamine hydrochloride (1.0-3.0 mg/kg).15 min after the administration, the 5-CSRT test is initiated.

(Drugs, Preparation and Administration Methods)

A suspension of 0.5% lurasidone hydrochloride in methylcellulose (MC) isorally administrated to the marmosets (0.1-30 mg/kg). On the other hand,L-745,870 which is a D₄ antagonist and Ro 10-5824 which is a D₄ agonistare dissolved in saline, and intramuscularly administrated to thefemoris area in a dose of 0.1-10 mg/kg and 0.1-3 mg/kg, respectively.These drugs are administrated 1-2 hours prior to the ketamineadministration.

(5-CSRT Test)

The 5-CSRT test is performed according to the following procedure whichis made by partially modifying that of the above reference(Neuropharmacology. 2006 Aug; 51(2): 238-50. Epub 2006 May 6.).

A system called CANTAB (Cambridge Neuropsychological Test AutomatedBattery) in which computerized tasks can be presented on a personalcomputer and a food reward is given for a correct answer, is employed. Apiece of Baumkuchen (0.1-0.3 g) is given to each individual through theCNTAB device as a food reward for the correct answer. The marmosetsreach out from the cage, answer the tasks provided by CANTAB device, andmake actions to obtain the food reward.

In the tasks of the 5-CSRT test, white lined circles having a diameterof 3 cm are presented at each vertex of an equilateral pentagon of 10 cmon a side, and only one of the 5 circles is lighted to yellow inside thewhite line for a period of 0.2 to 1.0 sec, then the yellow signal isblacked out. And, the marmosets can touch the lighting circle, and willbe given the reward for the correct answer if they touch the lightingcircle in the lighting period or within 15 sec after the extinction.Each task is loaded in every 5 sec, and the numbers of correct answers,wrong answers and omission, and time to respond to the task are recordedto evaluate the effect of drugs. The tasks consist of up to 30 tasks andup to 10 min of the total test period.

Example 3

Suitably designed clinical tests for evaluating deficits in attentionfunction in ADHD include Continuous Performance Test (CPT) (ReferenceURL1), Test of Variables of Attention (T.O.V.A) (Reference URL2).Alternatively, the improvement of deficits in attention function in ADHDby the compound and the combination drug of the present invention can beconfirmed using NIH Test of Attention (Reference URL2) operated in NIDCD(National institute on deafness and other communication disorders) ofthe NIH (National institute of health) and a clinical test based on newCPT (Reference URL3) which is a modified CPT test.

Reference URL1 ClinicalTrials.gov Identifier: NCT00546910

http://clinicaltrials.gov/ct2/show/NCT00546910

Reference URL2 ClinicalTrials.gov Identifier: NCT00776737

http://clinicaltrials.gov/ct2/show/NCT00776737

Reference URL3 ClinicalTrials.gov Identifier: NCT00646464

http://clinicaltrials.gov/ct2/show/NCT00646464

Example 4

The improvement of deficits in attention function in ADHD by thecompound and the combination drug of the present invention can beconfirmed using clinical tests based on the procedures described inReference 1 and Reference 2 as suitably designed clinical test forevaluating deficits in attention function in ADHD.

Reference 1: Rinsho Seishin Yakuri, vol. 12, issue. 9, Page 1957-1964(2009.09)Reference 2: Rinsho Seishin Yakuri, Vol. 12, issue 9, Page 1965-1977(2009.09)

Specifically, for example, by comparing the total score of ADHD RS-IV(ADHD Rating Scale-IV, Japanese edition (clinician version)) before andafter the administration of the compound or combintion drug of thepresent invention for a certain period (e.g., but not limited to, 8weeks) to 6 to 18 years old patients fulfilling the diagnostic criteriaof ADHD based on DSM-IV (Diagnostic and Statistical Manual of MentalDisorders, 4th. Edition), the improvement of deficits in attentionfunction which are the symptoms of ADHD can be confirmed (Reference 1,Page 1958-1960).

In the tests described above, conditiones such as patients,administration period, dose, and methods for assessment can beappropriately modefied. For example, evaluation according to scores ofInattention Subscale of ADHD RS-IV consisting of 9 terms, evaluationaccording to scores of Hyperactivity-Impulsiveness Subscale consistingof 9 terms, and/or evaluation according to ADHD generalized severity(CGI-ADHD-S) can be employed besides the total scores of ADHD RS-IV.Furthermore, other tests described in Reference 1 and Reference 2, andtests described in reference litertures in these References as well astests with appropriately modificated conditions of above tests can alsobe employed.

Example 5

According to the Y-maze test with juvenile stroke-prone spontaneouslyhypertensive rats (SHRSP), it is possible to evaluate the effect oflurasidone hydrochloride on attention function with spontaneousAlternation Behavior as an index of attention or concentration (BehavBrain Funct. 2005 Jul 15;1:9). Moreover, the effects of lurasidonehydrochloride on hyperactivity, which is one of core symptoms in ADHD,can be confirmed by the total number of the Arm Entries in a Y-mazetest.

(Y-Maze Test with SHRSP Rats)

Methods:

For the estimation of inattentive behavior, male juvenile SHRSP rats asan ADHD model and WKY rats as a reference (4 weeks old, n=8−10/group)are used. These animals are commercially available from Charles RiverLaboratories Japan, inc. or Hoshino Laboratory animals, inc. Lurasidonehydrochloride (e.g. 0.01, 0.03, 0.1, 0.3, 1, 3 and 10 mg/kg; produced byDainippon Sumitomo Pharma Co., Ltd.) is dissolved in 0.5%methylcellulose and 0.2% Tween 80, and is administratedintraperitoneally in a volume of 1 ml/kg, 30 minutes before theevaluation.

The method of Y-maze test was already reported elsewhere (BehavPharmacol. 2002 Feb;13(1):1-13). The “Arm Entry” means the entry of allfour paws into one arm. The “Alternation Behavior”, which is actualalternations, means the consecutive Arm Entries into three differentarms. The test is carried out for 8 minutes in one session and the totalnumber that a rat performs the Arm Entry is counted. The “MaximumAlternations” means the total number of the Arm Entries minus two. Anindex of attention is calculated as a percentage of the AlternationBehavior, as described below.

A percentage of Alternation Behavior=(the total number of theAlternation Behavior)/(the Maximum Alternations)×100

Results:

The increased number of total Arm Entries and the decreased percentageof Alternation Behavior were observed in the SHRSP rats compared to theWKY rats, indicating hyperactivity and inattention behavior in theSHRSP, respectively. After the administration of 0.1, 0.3 or 1.0 mg/kgof lurasidone hydrochloride, the Alternation Behavior was improved inthe SHRSP rats, with a statistical significance at 0.3 (p=0.0124) mg/kg.Furthermore the SHRSP to which lurasidone hydrochloride was given in adose of 0.1, 0.3 or 1.0 mg/kg showed the decreased number of total ArmEntries with a statistical significance at 0.3 (p=0.0096) and 1(p=0.0047) mg/kg, suggesting attenuated hyperactivity in the SHRSP.Thus, it is concluded that lurasidone hydrochloride improved inattentionbehavior and hyperactivity in SHRSP.

TABLE 3 Inattention Animal Dose % of Alternation Behavior species(mg/kg) mean ± SE WKY 0 82 ± 3 SHRSP 0 61 ± 2 SHRSP 0.1 70 ± 5 SHRSP 0.3 75 ± 2 * SHRSP 1.0 72 ± 2 * P < 0.05

TABLE 4 Hyperactivity Animal Dose Total Arm Entries species (mg/kg) mean± SE WKY 0 20 ± 1 SHRSP 0 27 ± 1 SHRSP 0.1 24 ± 1 SHRSP 0.3  22 ± 2 *SHRSP 1.0  21 ± 1 * * P < 0.05

Example 6

The elevated-plus maze with SHRSP makes it possible to estimate theeffects of lurasidone hydrochloride on impulsivity, which is one of mainsymptoms of ADHD (Behav Brain Funct. 2005 Jul 15;1:9). In particular, itis possible to confirm the effect of lurasidone hydrochloride onimpulsivity by measuring the spending time on open arms and/or thenumber of the entry into open arm in an elevated-plus maze. WKY rats areavailable as a normal animal.

(Elevated Plus Maze in SHRSP Rats) Methods:

The spending time on open arms in an elevated plus maze can be used asan index of impulsive-like behavior according to the method describedpreviously (Behav Pharmacol. 2002 Feb;13(1):1-13). For the estimation ofimpulsivity, male juvenile SHRSP rats as an ADHD model and WKY rats as areference (5 weeks old, n=8−10/group) are used. These animals arecommercially available from Charles River Laboratories Japan, inc. orHoshino Laboratory animals, inc. Lurasidone hydrochloride (e.g. 0.01,0.03, 0.1, 0.3, 1, 3 and 10 mg/kg; produced by Dainippon Sumitomo PharmaCo., Ltd.) is dissolved in 0.5% methylcellulose and 0.2% Tween 80, andis administrated intraperitoneally in a volume of 1 ml/kg, 30 minutesbefore the evaluation. A plus maze with two open and close arms (50cm×10 cm) is elevated 50 cm above a floor. After the administration oflurasidone hydrochloride, SHRSP or WKY rat is placed in the center areaand allowed to enter each arm freely for a 10 min session. Analysis isperformed with a video tracking software, EthoVision@XT (NoldusInformation Technology), in which the “Arm Entry” means an entry of abody center.

There is no significant difference in the spending time on closed armsbetween SHRSP and WKY, while SHRSP spends for a longer time on openarms. They indicate impulsive behavior and/or less anxiety in SHRSP. Thedecrease of time which SHRSP spends on open arms of an elevated-plusmaze indicates the improvement of impulsivity by the compound. Thus, theameliorating effect of lurasidone hydrochloride on impulsivity can beevaluated.

1. A method for improving behavior disorder which comprisesadministering a therapeutically effective amount of lurasidone or apharmaceutically acceptable acid addition salt thereof to a mammal inneed thereof.
 2. The method of claim 1 wherein the behavior disorder isaggression in ADHD.
 3. The method of claim 1 wherein the behaviordisorder is one or more disorders selected from the group consisting ofaggression against self and/or others, hostility, hyperactivity andsevere impulsiveness.
 4. A method for improving behavior disorder whichcomprises administering a therapeutically effective amount of lurasidoneor a pharmaceutically acceptable acid addition salt thereof and atherapeutically effective amount of a D₄ receptor agonist to a mammal inneed thereof
 5. The method of claim 4 wherein the behavior disorder isaggression in ADHD.
 6. The method of claim 4 wherein the behaviordisorder is one or more disorders selected from the group consisting ofaggression against self and/or others, hostility, hyperactivity andsevere impulsiveness.
 7. A method for improving attention function inschizophrenia and/or bipolar disorder which comprises administering atherapeutically effective amount of lurasidone or a pharmaceuticallyacceptable acid addition salt thereof to a mammal in need thereof.
 8. Amethod for improving attention function in schizophrenia and/or bipolardisorder which comprises administering a therapeutically effectiveamount of lurasidone or a pharmaceutically acceptable acid addition saltthereof and a therapeutically effective amount of a D₄ receptor agonistto a mammal in need thereof.
 9. The method of claim 4 wherein the D₄receptor agonist is one or more medicaments selected from the groupconsisting of PD-168077, ABT-724, ABT-670, F-15063, A-412997, FAUC-327,Ro-10-5824, CP-226269, PIP-3EA, FAUC-299, FAUC-3I6, FAUC-179, FAUC-356,FAUC-312, A-369508 and pharmaceutically acceptable salts thereof. 10.The method of claim 5 wherein the D₄ receptor agonist is one or moremedicaments selected from the group consisting of PD-168077, ABT-724,ABT-670, F-15063, A-412997, FAUC-327, Ro-10-5824, CP-226269, PIP-3EA,FAUC-299, FAUC-316, FAUC-179, FAUC-356, FAUC-312, A-369508 andpharmaceutically acceptable salts thereof.
 11. The method of claim 6wherein the D₄ receptor agonist is one or more medicaments selected fromthe group consisting of PD-168077, ABT-724, ABT-670, F-15063, A-412997,FAUC-327, Ro-10-5824, CP-226269, PIP-3EA, FAUC-299, FAUC-3I6, FAUC-179,FAUC-356, FAUC-312, A-369508 and pharmaceutically acceptable saltsthereof.
 12. The method of claim 8 wherein the D₄ receptor agonist isone or more medicaments selected from the group consisting of PD-168077,ABT-724, ABT-670, F-15063, A-412997, FAUC-327, Ro-10-5824, CP-226269,PIP-3EA, FAUC-299, FAUC-316, FAUC-179, FAUC-356, FAUC-312, A-369508 andpharmaceutically acceptable salts thereof.
 13. A pharmaceutical productcomprising lurasidone or a pharmaceutically acceptable acid additionsalt thereof and a D₄ receptor agonist.
 14. The pharmaceutical productof claim 13 which is the product for treating ADHD.
 15. Thepharmaceutical product of claim 13 wherein the D₄ receptor agonist isone or more medicaments selected from the group consisting of PD-168077,ABT-724, ABT-670, F-15063, A-412997, FAUC-327, Ro-10-5824, CP-226269,PIP-3EA, FAUC-299, FAUC-316, FAUC-179, FAUC-356, FAUC-312, A-369508 andpharmaceutically acceptable salts thereof.
 16. The pharmaceuticalproduct of claim 14 wherein the D₄ receptor agonist is one or moremedicaments selected from the group consisting of PD-168077, ABT-724,ABT-670, F-15063, A-412997, FAUC-327, Ro-10-5824, CP-226269, PIP-3EA,FAUC-299, FAUC-316, FAUC-179, FAUC-356, FAUC-312, A-369508 andpharmaceutically acceptable salts thereof.
 17. A medicament comprisinglurasidone or a pharmaceutically acceptable acid addition salt thereofand a D₄ receptor agonist.
 18. The medicament of claim 17 which is themedicament for treating ADHD.
 19. The medicament of claim 17 wherein theD₄ receptor agonist is one or more medicaments selected from the groupconsisting of PD-168077, ABT-724, ABT-670, F-15063, A-412997, FAUC-327,Ro-10-5824, CP-226269, PIP-3EA, FAUC-299, FAUC-316, FAUC-179, FAUC-356,FAUC-312, A-369508 and pharmaceutically acceptable salts thereof. 20.The medicament of claim 18 wherein the D₄ receptor agonist is one ormore medicaments selected from the group consisting of PD-168077,ABT-724, ABT-670, F-15063, A-412997, FAUC-327, Ro-10-5824, CP-226269,PIP-3EA, FAUC-299, FAUC-316, FAUC-179, FAUC-356, FAUC-312, A-369508 andpharmaceutically acceptable salts thereof.